The present invention relates to telecommunications, and in particular, to telephony-over-local area network (LAN) applications.
Suppliers of telecommunications equipment are increasingly providing telephony-over-LAN (TOL) applications. In such applications, telephony features are provided over or via the local area network rather than through a separate telephony network and private branch exchange. Such systems provide advantages in that all telecommunication functions are able to be provided over the same network.
However, such systems are disadvantageous in that proprietary telephones such as digital telephones have an enormous installed base of dedicated users. In addition, many digital phones are present on the market, which include sophisticated features, which users may not be willing to relearn. At present, no way of using such proprietary digital telephones in TOL applications is known. Accordingly, there is a need for support of proprietary digital phones over a local area network.
These disadvantages of the prior art are overcome in large part by a system and method for providing support for digital telephones on local area networks. According to a first embodiment, a digital telephone may be plugged into a special interface card in the user""s personal computer. The personal computer""s network interface card (NIC) is used to interface with the local area network. The telephone is used as a microphone and speaker such that the special interface card (PC interface card) converts the digital stream from the telephone into a digital stream which would normally be detected by a sound card. This converted digital stream can then fed into the LAN client software for handling as if the PC""s microphone had been used. Similarly, when voice is received from the network to the phone, the PC interface card emulates a sound card so that the LAN client software believes it is playing the voice over the sound card speaker, when in fact, voice is transmitted to the proprietary digital stream used by the proprietary digital telephone. In some specific embodiments, the local area network is an H.323 network and the PC interface card converts between H.323 and H.450 protocol digital streams and the proprietary digital stream.
According to an alternate embodiment, the telephone is coupled to an adapter bridge and, in turn to a local area network. The adapter bridge contains transcoding converters, a NIC, control processors and software, used to convert the digital protocol and the local area network protocol.